Two small planes with three people believed to be aboard collided over the ocean just outside the port of Los Angeles, prompting a massive search by dozens of boats and divers. There was no sign of survivors after hours of searching.

The collision occurred about 3:30 p.m. Friday on a dazzlingly sunny day, the Coast Guard said, with no immediate word on what might have caused it.

Two men ages 61 and 81 were aboard one plane, and a 72-year-old woman was aboard the other plane, Coast Guard Capt. Jennifer Williams said.

Searchers found wreckage, including a pilot's logbook, from the Beechcraft plane that was carrying the two men.

The plane flown by the woman is missing, and air traffic controllers saw two aircraft apparently run into each other on radar, leading authorities to conclude they must have collided.